This invention pertains to the art of electrical wireways and, more particularly, to subfloor trench duct assemblies. The invention is particularly applicable to sealing removable covers on electrical trench ducts and will be described with particular reference thereto. However, it will be appreciated by those skilled in the art that the invention has broader applications and may be used in other applications and environments.
The use of subfloor electrical trench duct assemblies has come to be a widely accepted method of supplying power, communication lines, and data lines to any number of stations within an office or industrial complex. These assemblies are capable of carrying a wide variety of different cables, and are easily accessible through an opening at the top area thereof to accommodate the addition or removal of cables without the necessity of having to pull or string them through the ducts.
Inasmuch as trench ducts must be placed in floors intended to receive a variety of different surface coverings, it is desirable to have means for allowing closure of the trench ducts without regard to the presence or absence of a floor covering. To accomplish this effectively without the necessity of having a dedicated design of trench duct cover for each separate floor covering, a separate strip between the body of the trench duct and the cover member has been used. Such strip may be placed in several different orientations to accommodate a particular flooring surface.
The type of strip arrangement used to form an intersection between the duct and the cover has varied vastly in configuration. One prior design comprises a rail having a generally Z-shaped cross-section wherein one base of the Z is longer than the other. Depending upon which base was placed perpendicular to the plane of the cover member, an intersection could be formed either flush with the cover or extending thereabove. A variety of other shapes were also attempted, including rail members having L-shaped cross-sections and generally rectangular cross-sections with axial ledges along one side thereof.
One problem associated with the use of subfloor trench ducts is their inherent susceptibility to spilled fluids, dust particles, and the like. It was, therefore, found to be desirable to provide some means for sealing the trench duct from exposure to these hazards by providing an axial sealing member between the cover and trench duct body. One prior construction created a seal by having the rail itself constructed from a plastic material. However, when the rail is constructed of plastic, it must necessarily be constructed of a semi-rigid material which is less likely to form an effective seal.
Electrical trench ducts are typically of such lengths that a plurality of covers disposed in end-to-end relation must be used. It is also desirable, in conjunction with sealing the cover longitudinally, to seal the intersection between adjacent ones of the covers.
It has, therefore, been considered desirable in the industry to develop an arrangement for overcoming the foregoing problems. The subject invention is deemed to meet these needs and others, and provides an assembly which allows a subfloor electrical trench to be adaptable to floor coverings of varying thickness, which provides an effective seal between a trench duct and an associated cover, and which provides an effective seal at the ends of adjacent covers.